Silencer structure

ABSTRACT

A silencer structure connected to an air duct includes a housing having two open ends and an accommodating chamber. The housing extends along an extending direction. At least one noise-reducing module is provided in the accommodating chamber and includes two spaced first noise-reducing plates extending along the extending direction. Respective two ends of the two first noise-reducing plates are connected to two fixing plates. A first cavity is formed between the two first noise-reducing plates. At least one second noise-reducing plate is provided in the first cavity. The second noise-reducing plate is perpendicular to the first noise-reducing plates and the extending direction. Each first noise-reducing plate is formed with a plurality of micro-perforations. Each micro-perforation is perpendicular to the extending direction. Each micro-perforation has a diameter less than a thickness of the first noise-reducing plates. The housing may be deflected at an angle relative to the air duct.

FIELD OF THE INVENTION

The present invention relates to a noise-reducing device, and more particularly to a noise-reducing device to be connected with an air duct of a pneumatic apparatus for reducing noise.

BACKGROUND OF THE INVENTION

In the environment where a pneumatic apparatus (such as air blower, air condition) is required for guiding the air flow to be inhaled and exhaled, an air duct is provided for the air flow to pass therethrough, but the mechanical and acoustic noises of the pneumatic apparatus will be conducted along the air duct to each air outlet. Therefore, a noise-reducing device is installed in the air duct to block the transmission of sound waves so as to reduce noise while allowing the air flow to pass through the air duct, thereby keeping the environment as silent as possible and improving the health of workers.

A conventional silencer 5, as shown in FIG. 1, includes a housing 51 having two open ends and at least one noise-reducing module 52 therein. The noise-reducing module 52 includes two perforated plates 53 that are spaced apart from each other. The perforated plates 53 each have a plurality of perforations 54 that are arranged uniformly. A cavity 55 is defined between the two perforated plates 53. The cavity 55 is filled with a porous material 56 (such as glass wool). According to this structure, the air flow and the mechanical and noises of the pneumatic apparatus are conducted to the air outlets along the air duct. When the air flow and the sound wave pass through the silencer 5 in the air duct, they pass through the perforations 54 of the perforated plates 53 to impact the walls of the perorations 54 and generate friction, and then enter the cavity 55 to impact the porous material 56 (such as fiberglass) to generate heat by frictional, which in turn converts kinetic energy into heat energy for noise reduction.

In the structure of the conventional silencer, the diameter of each perforation 54 of the perforated plate 53 is greater than the thickness of the perforated plate 53. For example, when the thickness of the perforated plate 53 of the housing 51 of the silencer 5 is 1 mm, the perforation 54 has a diameter of 1.5 mm or more. When the sound energy of the sound wave is in contact with the fiberglass 56 (or mineral wool) to generate heat, the kinetic energy is converted into heat energy to achieve the noise reduction effect. However, since the diameter of each perforation 54 of the perforated plate 53 is greater than the thickness of the perforated plate 53, the sound wave in the vicinity of the perforated plate 53 pass through the perforated plate 53 at an increasing speed, which cannot improve the noise reduction effect. Furthermore, since the fiberglass 56 filled between the two perforated plates 53 is a kind of artificial inorganic fiber which is made by crushing rock such as limestone, pyrophyllite, quartz sand, szaibelyite and fluorite into powder, stirring with sodium sulfate, thenardite and so on evenly, and melt blowing. Although glass wool is a substitute for asbestos and is not as dangerous as asbestos, glass wool has been proven to cause lung, skin and eye damage to workers who have been in contact with fiberglass for a long time. It is recommended to avoid using fiberglass.

In addition, Chinese Patent Publication No. CN206556223U discloses a wind turbine impedance composite noise-reducing device. The noise-reducing device includes a plurality of noise-reducing sheets provided in a housing. The noise-reducing sheets are arranged in a streamlined manner to reduce wind resistance. However, the inside of each noise-reducing sheet is filled with a material such as sound absorbing cotton, which results in lung, skin and eye damage to workers who have been in contact with the sound absorbing cotton for a long time.

Accordingly, the inventor of the present invention has devoted himself based on his many years of practical experiences to solve these problems.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a silencer structure. Through a noise-reducing module having a micro-perforated plate connected in an air duct, the noise caused by a pneumatic apparatus is hindered when flowing in the air duct, and the kinetic energy is converted into heat energy so as to reduce the noise.

In order to achieve the objective, the present invention provides a silencer structure. The silencer structure comprises a housing and at least one noise-reducing module. The housing has two open ends and a solid surface. The housing includes an accommodating chamber therein. The housing extends along an extending direction for guiding an air flow and a sound wave to flow along the extending direction.

The noise-reducing module is provided in the accommodating chamber. The noise-reducing module comprises two first noise-reducing plates that are spaced apart from each other. The two first noise-reducing plates extend along the extending direction. Respective two ends of the two first noise-reducing plates are connected to two fixing plates. A first cavity is formed between the two first noise-reducing plates. Each of the first noise-reducing plates is formed with a plurality of micro-perforations. Each of the micro-perforations is perpendicular to the extending direction. The micro-perforations each have a diameter less than a thickness of the first noise-reducing plates. At least one second noise-reducing plate is provided in the first cavity. The second noise-reducing plate is perpendicular to the first noise-reducing plates and the extending direction. A plurality of first noise-reducing spaces are formed between the first noise-reducing plates and the second noise-reducing plate, so that the heat energy consumption of the sound wave can be increased.

Preferably, the silencer structure further comprises at least one third noise-reducing plate. The third noise-reducing plate has the same structure as the first noise-reducing plates. The third noise-reducing plate is provided in the first noise-reducing space. The third noise-reducing plate is perpendicular to the first noise-reducing plates and the second noise-reducing plate and is parallel to the extending direction. Micro-perforations of the third noise-reducing plate are perpendicular to the extending direction.

Preferably, either side of the accommodating chamber is provided with a side noise-reducing module. The side noise-reducing module includes a side noise-reducing plate having the same structure as the first noise-reducing plates. The side noise-reducing plate is spaced apart from the housing by a second cavity. Two ends of the side noise-reducing plate are respectively connected to side fixing plates fixed to the housing. The side noise-reducing plate is provided with a plurality of micro-perforations, and each of the micro-perforations is perpendicular to the extending direction.

Preferably, the second cavity is provided with at least one fourth noise-reducing plate. The fourth noise-reducing plate is perpendicular to the side noise-reducing plate and the extending direction. A plurality of second noise-reducing spaces are formed between the side noise-reducing plate and the fourth noise-reducing plate.

Preferably, the second noise-reducing plate and the fourth noise-reducing plate have the same structure as the first noise-reducing plate, that is, the second noise-reducing plate and the fourth noise-reducing plate are provided with a plurality of micro-perforations. The micro-perforations of the second noise-reducing plate and the fourth noise-reducing plate are in the same direction as the extending direction.

Preferably, the first noise-reducing plates, the second noise-reducing plate, the third noise-reducing plate, the fourth noise-reducing plate and the side noise-reducing plate are flat plates.

Preferably, the extending direction of the housing is in the form of a straight line.

Preferably, the first noise-reducing plates and the side noise-reducing plate are curved plates extending in a bending direction.

Preferably, when the housing is assembled to an air duct, the housing is deflected at an angle relative to the air duct. For example, the housing is deflected at an angle of 90 degrees relative to the air duct.

Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a conventional noise-reducing box;

FIG. 2 is a perspective view of a first embodiment of the present invention;

FIG. 3 is an exploded view of the first embodiment of the present invention;

FIG. 4 is a sectional view of circle A of FIG. 3;

FIG. 5 is a schematic view of the first embodiment of the present invention when in use;

FIG. 6 is an exploded view of a second embodiment of the present invention;

FIG. 7 is a schematic view of the second embodiment of the present invention when in use;

FIG. 8 is a perspective view of a third embodiment of the present invention;

FIG. 8a is a partial enlarged view of the third embodiment of the present invention; and

FIG. 9 is a sectional view of a fourth embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIG. 2 and FIG. 3, a noise-reducing box structure according to a first embodiment of the present invention comprises a housing 1, at least one noise-reducing module 2, and two side noise-reducing modules 3. The housing 1 is a square housing that has two open ends and extends along an extending direction D1 and includes an accommodating chamber 11 therein. The two open ends of the housing 1 are respectively connected to an air duct (not shown), so that the air flow and the sound wave in the air duct can enter the accommodating chamber 11, and the air flow and sound wave are guided to flow in the extending direction D1. In this embodiment, the housing 1 may be made of a metal plate or a plastic plate, but not limited thereto, and extends in a straight line direction.

This embodiment includes two spaced noise-reducing modules 2 located in the accommodating chamber 11, not leaning against the left and right sides of the housing 1. Each noise-reducing module 2 includes two first noise-reducing plates 21 that are spaced apart from each other and two fixing plates 22. The first noise-reducing plates 21 are flat plates and extend along the extending direction D1 of the housing 1, that is, in the same direction as the housing 1. Respective two ends of the two first noise-reducing plates 21 are connected to the two fixing plates 22, thereby forming a hollow structure surrounded by the two first noise-reducing plates 21 and the two fixing plates 22 and defining a first cavity 23 formed between the two first noise-reducing plates 21. The first cavity 23 is provided with at least one second noise-reducing plate 25. The second noise-reducing plate 25 is provided perpendicular to the first noise-reducing plates 21 and the extending direction D1. A plurality of first noise-reducing spaces 27 are formed between the first noise-reducing plates 21 and the second noise-reducing plate 25.

The first noise-reducing plate 21 is formed with a plurality of micro-perforations 24. As shown in FIG. 4, each micro-perforation 24 is perpendicular to the surface of the first noise-reducing plate 21, and the diameter d of each micro-perforation 24 is less than the thickness t of the first noise-reducing plate 21. For example, the first noise-reducing plate 21 has a thickness t of 1 mm, and each micro-perforation 24 has a diameter d of less than 1 mm. Because the diameter d of each micro-perforation 24 is less than the thickness t of the first noise-reducing plate 21, the air flow and the sound wave generate a large resistance in the vicinity of each micro-perforation 24, to consume more noise energy. Therefore, the above features can improve the noise reduction effect. According to the orientation of the first noise-reducing plate 21 and the direction of the micro-perforations 24 in the first noise-reducing plate 21, as shown in FIG. 5, each micro-perforation 24 is perpendicular to the extending direction D1 of the housing 1.

As shown in FIG. 2 and FIG. 3, the two side noise-reducing modules 3 are provided in the accommodating chamber 11 at the left and right sides of the housing 1. Each side noise-reducing module 3 has a side noise-reducing plate 31 and two side fixing plates 32. The side noise-reducing plate 31 has the same structure as the first noise-reducing plate 21 described above, that is, the side noise-reducing plate 31 has a plurality of micro-perforations 34, and is spaced apart from the housing 1 to define a second cavity 33 (see FIG. 5) between the side noise-reducing plate 31 the housing 1. Two ends of the side noise-reducing plate 31 are connected to the side fixing plates 32 fixed to the housing 1. The second cavity 33 is provided with at least one fourth noise-reducing plate 35. The fourth noise-reducing plate 35 is perpendicular to the side noise-reducing plate 31 and the extending direction D1, so that a plurality of second noise-reducing spaces 37 are formed between the side noise-reducing plate 31 and the fourth noise-reducing plate 35.

FIG. 5 is a schematic view of the first embodiment of the present invention when in use. The two open ends of the housing 1 are respectively connected to the air duct 4, so that the air flow and the sound wave in the air duct 4 enter the accommodating chamber 11, and the housing 1 guides the air flow and the sound wave to flow in the extending direction D1. At this time, in addition to flowing forward, the sound wave laterally flows into the first cavity 23 through the plurality of micro-perforations 24 of the first noise-reducing plates 21 of the noise-reducing module 2, and laterally flows into the second cavity 33 through the plurality of micro-perforations 34 of the side noise-reducing plate 31 of the side noise-reducing module 3. Accordingly, the sound wave strikes the walls of the micro-perforations 24, 34 to generate heat by friction, so that the kinetic energy of the sound wave is converted into heat energy, thereby providing a noise reduction effect.

FIG. 6 illustrates a second embodiment of the present invention. The second embodiment is based on the structure of the first embodiment described above. The second noise-reducing plate 25 has the same structure as the first noise-reducing plate 21, that is, the second noise-reducing plate 25 has a plurality of micro-perforations 26, and the second noise-reducing plate 25 is perpendicular to the first noise-reducing plate 21. According to the orientation of the second noise-reducing plate 25 and the direction of the micro-perforations 26 in the second noise-reducing plate 25, as shown in FIG. 7, the micro-perforations 26 of the second noise-reducing plate 25 are in the same direction as the extending direction D1 of the housing 1.

Similarly, the fourth noise-reducing plate 35 has the same structure as the first noise-reducing plate 21, that is, the fourth noise-reducing plate 35 has a plurality of micro-perforations 36, and the fourth noise-reducing plate 35 is perpendicular to the side noise-reducing plate 31.

According to the orientation of the fourth noise-reducing plate 35 and the direction of the micro-perforations 36 in the fourth noise-reducing plate 35, as shown in FIG. 7, the micro-perforations 36 of the fourth noise-reducing plate 35 are in the same direction as the extending direction D1 of the housing 1.

Accordingly, when this embodiment is in use as shown in FIG. 7, the noise flows in the extending direction D1 of the housing 1, in addition to the flow state as in the first embodiment described above, the air flow enters the first cavity 23 and the second cavity 33 through the micro-perforations 24 of the first noise-reducing plate 21 and the micro-perforations 34 of the side noise-reducing plate 31, and passes through the micro-perforations 26 of the second noise-reducing plate 25 and the micro-perforations 36 of the fourth noise-reducing plate 35. Therefore, the air flow generates more impact than the foregoing first embodiment and generates more heat energy by friction, thereby reducing more kinetic energy of the air flow, so that the noise reduction effect is more significant.

FIG. 8 and FIG. 8a illustrate a third embodiment of the present invention. The third embodiment is based on the structure of the foregoing embodiment. In this embodiment, the present invention further comprises at least a third noise-reducing plate 28 having the same structure as the first noise-reducing plate 21. The third noise-reducing plate 28 is provided in the first noise-reducing space 27, and is perpendicular to the first noise-reducing plate 21 and the second noise-reducing plate 25, and is parallel to the extending direction D1. The micro-perforations of the third noise-reducing plate 28 are perpendicular to the extending direction D1.

Furthermore, FIG. 9 illustrates a fourth embodiment of the present invention. The fourth embodiment is based on the structure of the foregoing embodiment and changes the extending direction of the first noise-reducing plates 21 and the side noise-reducing plate 31. In this embodiment, the first noise-reducing plates 21 and the side noise-reducing plate 31 are curved plates each having a curvature corresponding to a bending direction D2, so that they can be applied to the curved portion of the air duct.

In the foregoing structure, the surface of the housing 1 is solid, that is, the surface of the housing 1 is not perforated.

In the above structure, the first cavity 23 does not have a filler.

In the above structure, the second cavity 33 does not have a filler.

When the housing 1 is assembled to the air duct 4, the housing 1 may be deflected at an angle relative to the air duct 4, for example, the housing 1 is deflected at an angle of 90 degrees relative to the air duct 4.

Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims. 

What is claimed is:
 1. A silencer structure, comprising: a housing having two open ends, the housing including an accommodating chamber therein and extending along an extending direction for guiding an air flow and a sound wave to flow along the extending direction; at least one noise-reducing module, provided in the accommodating chamber, comprising: two first noise-reducing plates that are spaced apart from each other, the two first noise-reducing plates extend along the extending direction, respective two ends of the two first noise-reducing plates being connected to two fixing plates, a first cavity being formed between the two first noise-reducing plates; each of the first noise-reducing plates being formed with a plurality of micro-perforations, each of the micro-perforations being perpendicular to the extending direction, the micro-perforations each having a diameter less than a thickness of the first noise-reducing plates; at least one second noise-reducing plate, provided in the first cavity, the second noise-reducing plate being perpendicular to the first noise-reducing plates and the extending direction, a plurality of first noise-reducing spaces being formed between the first noise-reducing plates and the second noise-reducing plate.
 2. The silencer structure as claimed in claim 1, wherein either side of the accommodating chamber is provided with a side noise-reducing module, the side noise-reducing module includes a side noise-reducing plate having the same structure as the first noise-reducing plates, the side noise-reducing plate is spaced apart from the housing by a second cavity, two ends of the side noise-reducing plate are respectively connected to side fixing plates fixed to the housing.
 3. The silencer structure as claimed in claim 2, wherein the second noise-reducing plate has the same structure as the first noise-reducing plate, and an axial direction of micro-perforations of the second noise-reducing plate is in the same direction as the extending direction.
 4. The silencer structure as claimed in claim 2, wherein the second cavity is provided with at least one fourth noise-reducing plate, the fourth noise-reducing plate is perpendicular to the side noise-reducing plate and the extending direction, and a plurality of second noise-reducing spaces are formed between the side noise-reducing plate and the fourth noise-reducing plate.
 5. The silencer structure as claimed in claim 4, wherein the fourth noise-reducing plate has the same structure as the first noise-reducing plate, and an axial direction of micro-perforations of the fourth noise-reducing plate is in the same direction as the extending direction.
 6. The silencer structure as claimed in claim 1, wherein the first noise-reducing space is provided with at least one third noise-reducing plate, the third noise-reducing plate has the same structure as the first noise-reducing plates, the third noise-reducing plate is perpendicular to the first noise-reducing plates and the second noise-reducing plate and is parallel to the extending direction, and micro-perforations of the third noise-reducing plate are perpendicular to the extending direction.
 7. The silencer structure as claimed in claim 3, wherein the first noise-reducing plates, the second noise-reducing plate and the third noise-reducing plate are flat plates.
 8. The silencer structure as claimed in claim 2, wherein the extending direction of the housing is in the form of a straight line.
 9. The silencer structure as claimed in claim 2, wherein the first noise-reducing plates and the side noise-reducing plate are curved plates extending in a bending direction.
 10. The silencer structure as claimed in claim 2, wherein the housing has a solid surface.
 11. The silencer structure as claimed in claim 2, wherein the housing is assembled to an air duct, the housing is deflected at an angle of 90 degrees relative to the air duct. 